Not sure how to handle AC

[Scott Wayne]

Sorry if this has been posted before but I couldn’t find anyone in my exact situation. Most people start with a bad compressor or something similar but all my stuff works.

I recently bought a 83 C20 with AC. The previous owner said the belt was slapping so he took it off and tossed it. I got a new belt on there and everything works, it just isn’t blowing cold air. It’s all original equipment except for the 134 adapters. There’s no sticker under the hood indicating that it’s been filled with 134 so I want to assume it only had R12 in it, but then why would it have adapters? Unless it was filled by the owner from a DIY kit?

So basically my issue is that the shop I went to didn’t want to touch it because they didn’t want to contaminate their equipment if it did it fact have R12 in the system. So I figured I could add R12 myself from an eBay kit, but then if it has 134 in the system I’m afraid I’ll Heck up the compressor. Any advice besides a 134 kit? I don’t have $1500 to put into this truck right now.

[Hoss C30]

Is the compressor kicking on at all?  If not, is there any pressure in the system at all?  If not, flush out the system and recharge with correct oil and R134.  It's not likely that it has R12 in it if it has the 134 retro fitting on it, but someone could have tried to add the 134 on top of R12.  Either way it needs to come out and be flushed properly and the proper oil installed and then look for a leak

[Scott Wayne]

No, the compressor never kicks on. I haven’t put gauges on it yet but just by quickly pressing in the shrader valve I can hear air escaping. The shop I went to said they wouldn’t vacuum out the system because it may have R12 in it, and if I’m not supposed to release that to the atmosphere then what option am I left with? It’s like the law doesn’t want us driving these old trucks anymore…

I’ve also heard that old AC equipment meant for R12 won’t work with 134, some people say it’s fine. Are you saying as long as I’ve emptied the R12 and changed the oil it should be ok?

[Captkaos]

If it has adaptors on it I would think it has R134.  Can you not ask the previous owner what they used. Getting R12 is next to impossible.
Putting R134 in a system that used R12 is no big deal as long as the system is flushed.

[Scott Wayne]

The previous owner just bought it to flip basically, he only had it for two years and it sat most the time. I would assume it had 134 too but the shops have to err on the side of caution I suppose.

[Mike81K10]

If it has the R134 retro fitting go to a shop and tell them to flush the system, pull a vacuum, and charge it with oil and R134. Tell them it is an R134 system as can be seen by the fittings.

[VileZambonie]

Sounds like they don't have a refrigerant identifier and you probably freaked them out with your unknown story so I don't blame them. I highly doubt someone did a retrofit and added R134a on top of R12.

[bd]

I agree with Vile.  Still, the absence of a retrofit sticker suggests the job wasn't performed professionally and may have been shortcut in some ways.

[Scott Wayne]

I went to Oreily’s today and got the quick recharge kit just to see what else I could find out.

As I was charging it the compressor starting kicking on and off, and finally stayed on once I had filled it enough. Before it had a chance to get cold the compressor started squeaking and the belt started jumping so I shut it off. I feel like the compressor is probably about to go out, or maybe it just needs ran a little, it’s been sitting for 2 years.

Any thoughts? Thanks y’all

[VileZambonie]

You can't just charge the system. It needs to be recovered, evacuated and recharged with the proper amount of refrigerant and oil. Overcharging, air and moisture is going to grenade the compressor and cause other issues. Just take it to someone who knows what they are doing and be happy.

[Captkaos]

Agreed with Vile.  It sounds like you have over charged it.  You will end up wasting a lot of money if you don't do it correctly.  Those compressors are not cheap and if they get overcharged it will grenade itself.

[ehjorten]

Those cans and single pressure gauge you get at the auto store are junk. You cannot tell what your AC system is doing without both a High Side and a Low Side pressure gauge.
First step would be to check both the high and low side pressure. Then depending on the system status, inject some UV dye to see where it may be leaking. Fix the issue. Vacuum down the system and make sure it is holding a vacuum. Maybe add a ounce or two of oil depending on that status of the system. Recharge with refrigerant.